The present inventor has proposed in PCT patent application PCT/AU86/00321 that the removal of prosthetic cement from the medullary canal of a patient's long bone can be facilitated during a joint prosthesis replacement operation by making two or more longitudinally extending cuts through the bone cement after removal of the old prosthesis. These cuts divide the originally tubular bone cement into a number of segments which may be conveniently levered away from the associated bone and removed from the medullary canal. In the aforementioned patent application means were described for forming such cuts through the prosthetic cement substantially without cutting into the underlying bone. These means included guide means to guide a saw blade along the line of intersection of a longitudinal plane extending through the bone, the prosthetic cement and a prosthetic cavity therein and a bone/prosthetic cement interface intersected by the plane.
The present inventor has also discovered that these guide means may be dispensed with if a cutting blade with a suitably profiled cutting edge is provided with depth limiting means which can bear against the surface of the prosthetic cavity adjacent the said plane to limit the depth to which the blade can cut into the prosthetic cement along the plane to the depth of the prosthetic cement along that plane (see PCT/AU88/00019).
It has been now found by the inventor that there may be some difficulty in forming appropriate depth limiting means on the blade and that if such means are formed on the blade that the blade is then dedicated to a single cut on a single patient and cannot be reused. It has also been found that as the blade is quite long but necessarily quite thin there may be difficulty in applying sufficient cutting pressure to the blade adjacent its tip to effectively cut through the full depth of the cement.